This work describes an easy synthesis (one pot) of MFe(2)O(4) (M = Co, Fe, Mn, and Ni) magnetic n... more This work describes an easy synthesis (one pot) of MFe(2)O(4) (M = Co, Fe, Mn, and Ni) magnetic nanoparticles MNPs by the thermal decomposition of Fe(Acac)(3)/M(Acac)(2) by using BMI·NTf(2) (1-n-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) or BMI·PF(6) (1-n-butyl-3-methylimidazolium hexafluorophosphate) ionic liquids (ILs) as recycling solvents and oleylamine as the reducing and surface modifier agent. The effects of reaction temperature and reaction time on the features of the magnetic nanomaterials (size and magnetic properties) were investigated. The growth of the MNPs is easily controlled in the IL by adjusting the reaction temperature and time, as inferred from Fe(3)O(4) MNPs obtained at 150 °C, 200 °C and 250 °C with mean diameters of 8, 10 and 15 nm, respectively. However, the thermal decomposition of Fe(Acac)(3) performed in a conventional high boiling point solvent (diphenyl ether, bp 259 °C), under a similar Fe to oleylamine molar ratio used in the IL synthesis, does not follow the same growth mechanism and rendered only smaller NPs of 5 nm mean diameter. All MNPs are covered by at least one monolayer of oleylamine making them readily dispersible in non-polar solvents. Besides the influence on the nanoparticles growth, which is important for the preparation of highly crystalline MNPs, the IL was easily recycled and has been used in at least 20 successive syntheses.
Page 1. DOI: 10.1002/cctc.201100221 Catalytic Aminolysis (Amide Formation) from Esters and Carbox... more Page 1. DOI: 10.1002/cctc.201100221 Catalytic Aminolysis (Amide Formation) from Esters and Carboxylic Acids: Mechanism, Enhanced Ionic Liquid Effect, and its Origin Vanda Maria de Oliveira,[b, c] Richard Silva de Jesus ...
A systematic approach to the development of methodology for the analysis of anionic solutes by ca... more A systematic approach to the development of methodology for the analysis of anionic solutes by capillary electrophoresis (CE) has been implemented. The strategy allows a rapid optimization of the experimental conditions and is based on the following steps: 1) A near optimum pH is chosen by inspection of the effective mobility versus pH curves of the sample components. The optimum pH lies in a region where the differences in the mobilities of all solutes are maximal. 2) An electrolyte system is selected by comparing the effective mobility of the electrolyte with the effective mobility of the primary components of the studied mixture. The appropriate electrolyte has a mobility as similar as possible to the mobility of the major components of the sample. 3) An initial experiment is run with the selected electrolyte system adjusted to the chosen pH and input values for other instrumental variables and electrolyte characteristics. 4) Depending on the degree of resolution obtained in the ...
The SERS (surface-enhanced Raman scattering) and SERRS (surface-enhanced resonant Raman scatterin... more The SERS (surface-enhanced Raman scattering) and SERRS (surface-enhanced resonant Raman scattering) spectra of iron(II) phthalocyanine (FePc) adsorbed onto a silver electrode have been investigated. The electrochemical SERRS has shown that the reduction of FePc molecule ...
This work describes an easy synthesis (one pot) of MFe(2)O(4) (M = Co, Fe, Mn, and Ni) magnetic n... more This work describes an easy synthesis (one pot) of MFe(2)O(4) (M = Co, Fe, Mn, and Ni) magnetic nanoparticles MNPs by the thermal decomposition of Fe(Acac)(3)/M(Acac)(2) by using BMI·NTf(2) (1-n-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) or BMI·PF(6) (1-n-butyl-3-methylimidazolium hexafluorophosphate) ionic liquids (ILs) as recycling solvents and oleylamine as the reducing and surface modifier agent. The effects of reaction temperature and reaction time on the features of the magnetic nanomaterials (size and magnetic properties) were investigated. The growth of the MNPs is easily controlled in the IL by adjusting the reaction temperature and time, as inferred from Fe(3)O(4) MNPs obtained at 150 °C, 200 °C and 250 °C with mean diameters of 8, 10 and 15 nm, respectively. However, the thermal decomposition of Fe(Acac)(3) performed in a conventional high boiling point solvent (diphenyl ether, bp 259 °C), under a similar Fe to oleylamine molar ratio used in the IL synthesis, does not follow the same growth mechanism and rendered only smaller NPs of 5 nm mean diameter. All MNPs are covered by at least one monolayer of oleylamine making them readily dispersible in non-polar solvents. Besides the influence on the nanoparticles growth, which is important for the preparation of highly crystalline MNPs, the IL was easily recycled and has been used in at least 20 successive syntheses.
Page 1. DOI: 10.1002/cctc.201100221 Catalytic Aminolysis (Amide Formation) from Esters and Carbox... more Page 1. DOI: 10.1002/cctc.201100221 Catalytic Aminolysis (Amide Formation) from Esters and Carboxylic Acids: Mechanism, Enhanced Ionic Liquid Effect, and its Origin Vanda Maria de Oliveira,[b, c] Richard Silva de Jesus ...
A systematic approach to the development of methodology for the analysis of anionic solutes by ca... more A systematic approach to the development of methodology for the analysis of anionic solutes by capillary electrophoresis (CE) has been implemented. The strategy allows a rapid optimization of the experimental conditions and is based on the following steps: 1) A near optimum pH is chosen by inspection of the effective mobility versus pH curves of the sample components. The optimum pH lies in a region where the differences in the mobilities of all solutes are maximal. 2) An electrolyte system is selected by comparing the effective mobility of the electrolyte with the effective mobility of the primary components of the studied mixture. The appropriate electrolyte has a mobility as similar as possible to the mobility of the major components of the sample. 3) An initial experiment is run with the selected electrolyte system adjusted to the chosen pH and input values for other instrumental variables and electrolyte characteristics. 4) Depending on the degree of resolution obtained in the ...
The SERS (surface-enhanced Raman scattering) and SERRS (surface-enhanced resonant Raman scatterin... more The SERS (surface-enhanced Raman scattering) and SERRS (surface-enhanced resonant Raman scattering) spectra of iron(II) phthalocyanine (FePc) adsorbed onto a silver electrode have been investigated. The electrochemical SERRS has shown that the reduction of FePc molecule ...
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